Endoscope-type devices are used in many different fields of application, such as medicine, for example endoscopy, particularly for emergency intubation, but also in engineering, for example as endoscope-type tools with an endoscope-type, flexible and formable shaft, and in general fields of application such as the controlled movement of extremities, particularly human extremities.
Intubation is the introduction of a tube (or a catheter) consisting of rubber or plastic material into the larynx and then into the trachea of the individual. It serves to maintain an effective exchange of gases, which is essential for providing organs with oxygen, among other things, and which is usually effected by respiration. In situations in which the patient is not capable of breathing himself any more as a result of an illness, an injury or medication, for example when a narcosis is carried out, artificial respiration has to be carried out. A prerequisite for this artificial respiration is a secure connection between the respirator and the patient's respiratory tract. In order to ensure that air is supplied to the respiratory organs only, without any air reaching the digestive tract via the esophagus, the tube is pushed with its distal end into the trachea via the mouth or the nose and is positioned there in such a way that both lobes of the lung are aerated. At the proximal end, the tube is connected with the tube system of the respirator via a standardized projection (connector).
If the tip of the tube is not positioned in the trachea, the lobes of the lung are not aerated. In this case, the blood flowing through the lung is not enriched with oxygen to a sufficient extent, and the organs are not provided with oxygen any more. Depending on how long the organs are not supplied with oxygen to a sufficient extent, apart from the  complete restoration of all bodily functions, permanent cerebral injuries (such as a coma) or even death because of cardiac arrest might be possible. Faulty intubation, meaning those maneuvers of intubation in which the tube is not positioned correctly and the tip of the tube rests in the esophagus instead of the trachea, for example, will have the same consequences.
There are several methods and shapes of tubes to ensure secure positioning of the tip of the tube. With patients for whom no special anatomic or pathological conditions are to be taken into account, intubation is usually easy and fast to carry out with the usual methods, mainly the laryngoscopical intubation. However, difficulties may arise if there are pathological changes or anatomic peculiarities; in this case, the patient, who is not breathing any more, is subjected to artificial respiration by applying a combination of laryngoscopical intubation and fiber-optical intubation or by using devices employed specifically for this purpose.
In emergency intubation, which usually means the intubation of a person who has become unconscious and whose lung is liable to fill with water, it is necessary to supply air from outside as soon as possible in order to minimize the risk of lung injury.
In an emergency situation, i.e. at the site of the accident and usually not in a hospital, this is done by means of laryngoscopical intubation; here, using a laryngoscope, lifting the tongue root and the epiglottis, the patient's pharynx is opened in order to gain a good view on the entrance to the larynx, the rima glottidis. If the rima glottidis is only partially visible, it is difficult to introduce the tube. One manages by changing the shape of the tube in its longitudinal axis until the tip of the tube can securely reach the entrance to the trachea. By now, this has been done by internally splinting the tube by means of a guide rod in the form of a flexible wire sheathed with plastic material which is inserted therein, which is so stable after bending that it transfers its shape in the longitudinal axis to the elastic tube. It is displaceable in the longitudinal axis within the tube, so it may also project from the distal tube end with its soft tip. Depending on the anatomic  conditions, the guide rod is bent in such a way that its tip can be pushed through the rima glottidis and the tip of the tube can then be positioned in the trachea by sliding it over the guide rod. If the rima glottidis is not visible because of anatomic difficulties, so the path of the tube or the guide rod cannot be watched when it is pushed forward, there is a higher risk of injuries and a markedly reduced hitting accuracy. Although there are special instruments which are to make it possible to see the rima glottidis even under difficult conditions, the view through the tube is often obstructed when they are used because of the narrow conditions. For this reason, in difficult cases, the application of laryngoscopical intubation is not favorable.
Therefore, in these cases, fiber-optical intubation is preferably applied, in which an endoscope of the type mentioned at the beginning is used in order to find the entrance to the trachea and to illuminate and make visible the area to be inspected. Furthermore, by means of a mechanism mounted on the holding portion of the endoscope, the position of the tip of the endoscope can be changed, and it can therefore be visibly pushed through the rima glottidis. The tube previously placed upon the tube of the endoscope is then pushed forward as far as into the trachea; then, the endoscope is pulled out of the tube which has been positioned correctly, and the tube is fixed to the patient's head and is connected with the respirator.
However, the fiber-optical method cannot be carried out optimally in all cases, either. It is particularly different if the patient is lying on his back and his musculature is slackened, because the tongue root falls back, thus blocking the path to the trachea. Furthermore, as one hand is required to guide the endoscope—usually by means of the surrounding tube—in fiber-optical intubation and a second hand is required to operate the mechanism of the endoscope, another person is necessary to lift the tongue root by means of a laryngoscope; however, such a person is not necessarily present in case of an emergency. 
In the document EP 0 742 026 A, a flexible and simultaneously formable endoscope with a viewing lens was therefore suggested, over which a tube can be slid. Here, formability and flexibility was to be obtained by an articulated rod whose individual adjacent links with convex or concave surfaces could be tensed by tensional or compressive forces. What was disadvantageous, however, was that tests during manufacturing revealed that this principle is very complex because of the frictional forces which are difficult to control and that sufficient flexibility with simultaneously adjustable stiffness cannot be realized with this endoscope.